Now that Mozilla has finally released Firefox 4 to the masses, it's time for a BIG browser benchmark where we take the leading browsers and pit them against four of the toughest benchmark tests available to see which is the tortoise, and which is the hare.

Now that Mozilla has finally released Firefox 4 to the masses, it's time for a BIG browser benchmark where we take the leading browsers and pit them against four of the toughest benchmark tests available to see which is the tortoise, and which is the hare.

OK, so what conclusions can we draw? Well, let's begin with the obvious and say that Internet Explorer 9 64-bit is an absolute dog when it comes to JavaScript performance. This is to be expected given that IE 9 64-bit is using an older, slower JavaScript engine, while IE 9 32-bit was using the newer, more efficient Chakra JIT.

OK, with the loser out of the way, what's the winning browser? Well, out of the four benchmarks, Chrome 10 won two, IE9 32-bit won one and Firefox 4 won one, so in the strictest sense, Chrome 10 is the winner. But in the SunSpider test there is so little separating the four fastest browsers (a shade over 40 milliseconds) that you could almost say it is a tie. Then there's the V8 test, which Chrome 10 aces, but then that's to be expected given that Google, by its own admission, use that benchmark to tune the V8 JavaScript engine.

So, what's the conclusion? Simple, IE9 64-bit is shockingly bad, and all the other browsers are, on the whole, pretty evenly matched. I'm pleasantly surprised that IE9 32-bit actually aces the SunSpider test, but I expect that over the coming weeks Google will manage to catch up and take the lead once again (Microsoft's painfully slow update cycle for IE (especially compared with Google's aggressive update cycle) works against it in the long run. Microsoft has worked hard on IE, taking it from being the slowest in the pack to one of the fastest. That itself is worthy of recognition.

Note: The 64-bit version of IE is only available to those with a 64-bit OS, and even then you've got to go searching for it. My advice, don't bother.

Bottom line, I really don't think that JavaScript performance is an issue any more, and certainly in real-world testing it's hard to see a difference between the browsers (some HTML 5 sites not withstanding, given that many are optimized for a particular browser). In fact, unless one of the players managed to boost JavaScript performance by an order of magnitude, shaving a few milliseconds off here and there hardly matters any more.